. 2011 May 16;26(8):1987–1996. doi: 10.1093/humrep/der147

Table IV.

Survival of embryos after freezing and thawing.

	Embryos frozen in a medium containing
	0.1 M sucrose (control)	0.3 M sucrose (intervention)	OR (95% CI); P
Number of embryos frozen	472	500
Total number of embryos (%) thawed^a	317 (67%)^b	269 (54%)^c
Number of embryos (%) recovered	316 (67%)	267 (53%)
Number of embryos (%) fully intact	180/316 (57%)	196/267 (73%)	2.9 (1.6, 5.4); <0.001^d
Number of embryos (%) with ≥50% of blastomeres intact	252/316 (80%)	239/267 (90%)	2.4 (1.3, 4.2); 0.003^d

OR, odds ratio; CI, confidence interval.

^aIncludes embryos thawed for couples intending embryo transfer and those for couples who allowed observation of their embryos before they were discarded.

^bFifteen embryos frozen on Day 1, 290 on Day 2 and 12 on Day 3 post insemination.

^cTwenty three embryos frozen on Day 1, 224 on Day 2 and 22 on Day 3 post insemination.

^dRandom effect logistic model includes random effect for couple and treatment effect is adjusted for day of embryo freezing.